Summer heat and hospital admissions: the effect of temperature on our health

The Barcelona Institute for Global Health (ISGlobal), together with the French National Institute for Health and Medical Research (Inserm), has analysed hospital admissions in Spain during the hot summer months – from June to September – between 2006 and 2019.

The analysis, based on data from the peninsular provinces and the Balearic Islands, includes 11.2 million admissions. When analysed together with the daily temperature, relative humidity and atmospheric pollutants, it showed that there is an impact of heat on hospitalizations.

The research found that the most vulnerable population are children under 1 year of age and those over 85. Gender differences were also discovered: women are more sensitive to heat, so they are more likely to be admitted than men due to parasitic, endocrine and metabolic, respiratory or urinary diseases. In fact, the diseases most affected by heat in general were metabolic and obesity-related disorders, followed by kidney failure, urinary tract infection and sepsis, among others.

“The increase in hospitalizations on hot days appears to be related to how our body regulates its own temperature”

Hicham Achebak, ISGlobal, and first author of the article

That the risk of hospitalization for metabolic diseases almost doubles on hot days is due to the fact that when it’s hot, our body tries to regulate its temperature. This is possible thanks to sweating and dilation of the blood vessels, but in the case of metabolic disorders, these processes do not work properly.

What is evident from this research, published in Environmental Health Perspectives, is that heat waves and extreme temperatures have a major impact on health and hospital admissions. That is why the research group believes heat alerts should not only focus on heat waves but also on cases of non-persistent extreme temperatures.